[TUHS] History of non-Bell C compilers?

[Paul Winalski]

On 3/7/24, Tom Lyon <pugs78 at gmail.com> wrote:
> For no good reason, I've been wondering about the early history of C
> compilers that were not derived from Ritchie, Johnson, and Snyder at Bell.
> Especially for x86.  Anyone have tales?
> Were any of those compilers ever used to port UNIX?
>
[topic of interest to COFF, as well, I think]

DEC's Ultrix for VAX and MIPS used off-the-shelf Unix cc.  I don't
recall what they used for Alpha.

The C compiler for VAX/VMS was written by Dave Cutler's team at
DECwest in Seattle.  The C front end generated intermediate language
(IL) for Cutler's VAX Code Generator (VCG), which was designed to be a
common back end for DEC's compilers for VAX/VMS.  His team also
licensed the Freiburghouse PL/I front end (commercial version of a
PL/I compiler originally done for Multics) and modified it to generate
VCG IL.  The VCG was also the back end for DEC's Ada compiler.  VCG
was superseded by the GEM back end, which supported Alpha and Itanium.
A port of GEM to x86 was in progress at the time Compaq sold off the
Alpha technology (including GEM and its C and Fortran front ends) to
Intel.